fix(pi): make the search provider drift guards actually fire

The "you cannot add a provider without mirroring it" story rested on two
mechanisms that did not hold. Verified by adding a fifth provider to
`PI_SEARCH_PROVIDERS` and running the build: it produced only two errors, and
every test still passed.

- `normalizePiSearchRecords` assigns to `let built` inside its switch rather
  than returning, so unlike its two siblings a missing case was not a type
  error — it silently normalized the new provider to zero results. Added an
  explicit `never` check.

- The sandbox copy's `normalizeRecords` used a trailing `else` for Firecrawl,
  so an unmirrored provider was silently normalized with Firecrawl's field
  names; `extractRecords` did the same with its `payload.data` tail. Both now
  test for `firecrawl` explicitly and throw otherwise.

- `Record<PiSearchProvider, ...>` on the `TOOLS` and `payloads` fixtures looked
  like exhaustiveness guards but are inert: `apps/sim/tsconfig.json` excludes
  `**/*.test.ts`, and vitest transpiles without typechecking. Both suites drive
  their providers off `Object.keys(fixture)`, so a missing provider was skipped
  rather than failed. Each suite now asserts its fixture covers the registry.

Re-running the same experiment now yields three compile errors plus two test
failures naming the missing fixtures.

Author: icecrasher321

apps/sim/executor/handlers/pi/search/extension-source.test.ts

@@ -11,7 +11,7 @@ import { tmpdir } from 'node:os'
 import { join } from 'node:path'
 import { pathToFileURL } from 'node:url'
 import { afterAll, beforeAll, beforeEach, describe, expect, it, vi } from 'vitest'
-import type { PiSearchProvider } from '@/executor/handlers/pi/keys'
+import { PI_SEARCH_PROVIDERS, type PiSearchProvider } from '@/executor/handlers/pi/keys'
 import {
   PI_SEARCH_API_KEY_ENV_VAR,
   PI_SEARCH_EXTENSION_PATH,
@@ -258,6 +258,13 @@ describe('normalization parity with the host adapter', () => {
     },
   }
 
+  // `Record<PiSearchProvider, unknown>` on `payloads` is not enforced anywhere — test files are
+  // excluded from tsconfig and vitest only transpiles — so a provider missing here would be quietly
+  // skipped by `it.each` instead of failing. This assertion is what actually holds the copies together.
+  it('covers every registered search provider', () => {
+    expect(Object.keys(payloads).sort()).toEqual(Object.keys(PI_SEARCH_PROVIDERS).sort())
+  })
+
   it.each(Object.keys(payloads) as PiSearchProvider[])(
     'produces the same envelope as normalize.ts for %s',
     async (provider) => {

apps/sim/executor/handlers/pi/search/extension-source.ts

@@ -177,6 +177,9 @@ function extractRecords(provider, payload) {
   if (provider === "serper") {
     return Array.isArray(payload.organic) ? payload.organic : []
   }
+  if (provider !== "firecrawl") {
+    throw new Error("Unsupported search provider: " + provider)
+  }
   const data = payload.data
   if (Array.isArray(data)) return data
   if (!isRecord(data)) return []
@@ -210,12 +213,16 @@ function normalizeRecords(provider, records, limit) {
         snippet: firstText(record.excerpts),
         publishedDate: firstText(record.publish_date, record.publishedDate),
       })
-    } else {
+    } else if (provider === "firecrawl") {
       built = buildResult({
         title: record.title,
         url: record.url,
         snippet: firstText(record.description, record.snippet),
       })
+    } else {
+      // Never the trailing else: an unmirrored provider would otherwise be normalized with
+      // Firecrawl's field names and quietly return nothing.
+      throw new Error("Unsupported search provider: " + provider)
     }
     if (built) results.push(built)
   }

apps/sim/executor/handlers/pi/search/normalize.ts

@@ -311,6 +311,13 @@ export function normalizePiSearchRecords(
           snippet: firstText(record.description, record.snippet),
         })
         break
+      default: {
+        // Unlike the sibling switches this one assigns rather than returns, so without an explicit
+        // exhaustiveness check a new provider would compile clean and silently normalize to zero
+        // results. `satisfies never` fails the build instead.
+        const unhandled: never = provider
+        throw new Error(`Unhandled Pi search provider: ${String(unhandled)}`)
+      }
     }
 
     if (built) results.push(built)

apps/sim/executor/handlers/pi/search/parity.test.ts

@@ -15,7 +15,7 @@ import { tmpdir } from 'node:os'
 import { join } from 'node:path'
 import { pathToFileURL } from 'node:url'
 import { afterAll, beforeAll, beforeEach, describe, expect, it, vi } from 'vitest'
-import type { PiSearchProvider } from '@/executor/handlers/pi/keys'
+import { PI_SEARCH_PROVIDERS, type PiSearchProvider } from '@/executor/handlers/pi/keys'
 import {
   PI_SEARCH_API_KEY_ENV_VAR,
   PI_SEARCH_EXTENSION_SOURCE,
@@ -110,6 +110,15 @@ function buildHostRequest(provider: PiSearchProvider): CapturedRequest {
   }
 }
 
+// `Record<PiSearchProvider, ...>` on TOOLS looks like it enforces this, but `**/*.test.ts` is
+// excluded from tsconfig and vitest only transpiles — so a provider missing from the fixture would
+// silently be skipped by `describe.each` rather than failing. This assertion is the real gate.
+describe('fixture coverage', () => {
+  it('exercises every registered search provider', () => {
+    expect(Object.keys(TOOLS).sort()).toEqual(Object.keys(PI_SEARCH_PROVIDERS).sort())
+  })
+})
+
 describe.each(Object.keys(TOOLS) as PiSearchProvider[])('%s request parity', (provider) => {
   it('sends the same url, headers, and body from the sandbox as from the host', async () => {
     const sandbox = await captureExtensionRequest(provider)